System and method for enhancing speech of a diver wearing a mouthpiece

ABSTRACT

Embodiments described herein provide a system, apparatus and methods to enable a diver to communicate more clearly with other divers or locations Embodiments process the speech to add clarity, or otherwise convert speech into an outputted form that is more intelligible e.g. so as to simulate the diver&#39;s unhindered speech. Embodiments provide hardware and software for receiving and recognizing hindered speech of a diver (e.g., speech hindered by a mouthpiece) and then augmenting the speech with generated output sounds corresponding to the intended speech sound or generating or replacing at least some of the diver&#39;s speech with synthesized words. The output sounds may be in the speaker&#39;s own voice or a synthesized voice. Embodiments may be configured to add clarity to and/or augment speech that is hindered by the wearing of a mouthpiece from a snorkel, SCUBA or other diving apparatus.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional patent applicationSer. No. 61/483,610 filed May 6, 2011; entitled SYSTEM AND METHOD FORENHANCING SPEECH OF A DIVER WEARING A MOUTHPIECE, which is fullyincorporated by reference for all purposes.

This application is related to the following applications: U.S. patentapplication Ser. No. 13/398,718 filed, Feb. 16, 2012; entitled,Apparatus, System And Method For Underwater Signaling Of Audio MessagesTo A Diver”; U.S. patent application Ser. No. 13/231,881, filed Sep. 13,2011; entitled, “Self-Propelled Buoy for Monitoring Underwater Objects”;U.S. patent application Ser. No. 13/237,912, filed Sep. 20, 2011;entitled, “Device, System and Method for Monitoring and CommunicatingBiometric Data of a Diver”; U.S. patent application Ser. No. 13/457,456,filed Apr. 26, 2012; entitled, “Mouthpiece for Measurement of BiometricData of a Diver and Underwater Communication and U.S. patent applicationSer. No. 13/352,249 filed Jan. 17, 2012; entitled, “Apparatus, Systemand Method for Underwater Voice Communication by a Diver,” all of whichare fully incorporated by reference for all purposes.

FIELD OF THE INVENTION

Embodiments described herein relate to a system for underwater voicecommunication. More specifically, embodiments described herein relate toa system and method for underwater communication by a diver, such asSCUBA or skin diver. Still more specifically, the present embodimentsrelate to a system for enhancing speech of a diver wearing a mouthpiece.

BACKGROUND

Since the early days of SCUBA (Self-Contained Underwater BreathingApparatus) diving, communication between SCUBA divers has been an issue.This is due to the fact that the use of the SCUBA includes a mouthpieceworn by the divers which precludes direct voice communication. However,because of the risks involved in an underwater environment, divers havea critical need to communicate a variety of safety related messages totheir fellow divers, e.g., communicating the amount of air they haveremaining. As a result, a series of hand signs have been developed forunderwater communication, but they only cover a very limited number ofmessages and cannot quickly get other divers' attention in criticalsituations. Various underwater graphical display devices have also beendeveloped, but they have the same limitation as the hand signs.Furthermore, these devices which are worn on the diver's wrist or armrequire the diver to divert his or her attention from what they aredoing to look at the display. However, divers typically dive with theirheads up to watch for their directions and with their arms besides theirtorsos to reduce the water resistance. Henceforth, the diver's naturaldiving position is not conducive to monitoring a visual alert on theirwrist or elsewhere (e.g., arm or waist). This is even true for visualalerts being projected on the diver's face mask since the diver'sattention is more focused on what is in front of them and not on what isprojected on his or her face mask.

Acoustic alarm systems have also been developed, but they are code-basedinstead of voice-based. Therefore, such system can only communicate alimited number of messages and require the diver to understand theirindividual codes. Also, none of these devices provide for communicationbetween divers and a surface craft such as a dive boat (a boat whichtransports and supports the divers). Further, none of these devicesprovides for communication between divers who are not in very closeproximity. Thus, there is a need for an apparatus and an approachallowing for voice-based alerts to be communicated to the divers, forvoice communication between divers while they are underwater, as well asfor voice communication between divers and the surface craft.

BRIEF DESCRIPTION OF THE INVENTION

Embodiments described herein provide a system, apparatus and methods forunderwater voice communication. One of the challenges of such a systemis recognizing the speech of the diver when he or she is wearing amouthpiece which limits the diver's the ability to pronounce varioussounds. In some embodiments, an underwater communication system and/ordevice is provided to enable a diver (or other underwater person such asa snorkeler) to communicate more clearly with other divers or locations,such as surface boat locations.

Embodiments provide for the system including hardware and software forreceiving and recognizing hindered speech (“hindered voice input”) andthen augmenting the speech with generated sounds (“voice output”)corresponding to the intended speech sound or generating or replacing atleast some of the diver's speech with synthesized words. The output maybe in the speaker's own voice or a synthesized voice. In at least oneembodiment, the hindered speech is made by a diver speaking with amouthpiece in place. In an embodiment, the system comprises speechenhancement hardware to receive and recognize voice input, and to signalan output, in the context of an underwater breathing apparatus.

Embodiments include hardware, software or combinations thereof forprocessing obstructed spoken utterances of a diver who, under typicalconditions, uses a mouthpiece and/or breathing apparatus that hindersand/or impedes normal speech. Embodiments process the speech to addclarity, or otherwise convert speech into an outputted form that is moreintelligible (e.g. so as to simulate the diver's speech withoutobstruction from the mouthpiece).

In some embodiments, a device or apparatus is provided which includesmemory resources (e.g. a buffer) for storing the diver's voice input.Further processing resources can be provided to recognize and substitutefor obstructed or other unclear spoken utterances with speech output(synthesized or simulated) that corrects or otherwise clarifies theobstructed speech of the user.

In some embodiments, the voice output substitutes sounds whereappropriate (e.g., by “blending” the substitutes with the originals) andplays back the blended speech as a whole so that the listener does nothear any breaks in the diver's spoken messages. For example, the modulecan include routines for removing or otherwise minimizing any pauses inthe voice output so that the blended speech sounds continuous to thelistener. In performing such an operation, the module can take asampling of the diver's speech to determine the average interval betweenwords and then use that to look for gaps which are larger than theaverage interval.

Still further, some embodiments allow a diver to speak and have two wayvoice communication with other divers and surface ships without havingto remove their mouthpiece and without having any other specializedequipment. Such embodiments also allow the diver to communicate a fullrange of speech sounds to allow normal speech while the mouthpiece is inplace. Embodiments of the invention also allow the diver to hear audiomessages such as acoustic alarms, voice messages and prompts from aportable dive computer or other underwater electronic device. In use,such embodiments allow the diver to perform various tasks whilereceiving a variety of information including voice prompts and commandswithout having to look at a display, gauge or like device or apparatus.This enables the divers to stay focused on their task and/or theirunderwater environment, thus improving safety and their divingexperience. Still other embodiments of the invention allow the diver tohear music, radio or other audio input while they are underwater. Stillother embodiments can provide the diver with an acoustic input of soundsfrom the body of water in which he or she is diving allowing the diverto hear the sounds of underwater marine life as well as the sounds ofsurface craft.

An embodiment of a mouthpiece apparatus for underwater voicecommunication by a diver comprises a mouthpiece having an exteriorcoupling element for coupling to an air hose or other conduit of a SCUBA(or other underwater breathing apparatus) and an interior portioncoupled to the coupling element and worn in the diver's mouth. Thecoupling element may be coupled directly to the air hose or to a fittingon the air hose. The coupling element and interior portion can include alumen for the passage of respired air by the diver. The interior portionhas a curved shaped corresponding to a shape of the diver's mouth andhas attached right and left bite structures. The bite structures includeupper and lower surfaces for engaging a bite surface of the user's upperand lower teeth. One or both of the bite structures may include aretaining flange which can be perpendicular to a bite surface of thebite structure for retaining the mouthpiece in the diver's mouth.

An acoustic transducer is positioned on the top surface of at least oneof the left or right bite structures. The acoustic transducer isconfigured to transduce an electrical signal input (e.g., from anothercommunication device or a dive computer) into an acoustic output and toacoustically couple to the diver's upper teeth in order to conduct theacoustic output from the diver's upper teeth through the diver's skullto generate audible sound in at least one of the diver's ears (e.g., tocochlea) when the diver is wearing the mouthpiece. Typically, theacoustic transducer is positioned to engage the upper (e.g., maxillary)back teeth of the diver's mouth, but may be positioned to engage anysuitable tooth or group of teeth in the diver's mouth. Also, transducerproperties can be tuned or otherwise adjusted. A microphone ispositioned in or on the mouthpiece for detecting the diver's voice andgenerating an electrical output signal when the diver is wearing themouthpiece. The microphone may be recessed or otherwise positioned toreduce breathing sounds. This microphone output can be sent to anunderwater communication device for underwater transmission to anotherdiver(s) or to a surface ship. In many embodiments, the communicationdevice may correspond to an ultrasonic or other acoustical transmissiondevice which transduces the electrical output signal into an acousticsignal, which is transmitted by the acoustical transmission device.Also, in various embodiments, one or both of the communication device ormicrophone may include a filter (e.g., high pass, low pass, etc.) forfiltering out breath and related sounds of the diver from his or herspoken words.

In an exemplary embodiment of using the invention, the diver attaches anembodiment of the mouthpiece to a fitting on a regulator or othercomponent of his or her SCUBA gear. For embodiments having electricalcouplings on the mouthpiece, the diver may then connect them to theunderwater communication device. He or she may perform a few quick teststo assure that the communication system is working. Such tests caninclude putting in the mouthpiece and saying some test phrases (e.g.,“testing 1, 2, 3,” etc.) while looking at a display on or coupled to thecommunication device to assure that a signal from the microphone isgetting to the communication device. The test for the acoustictransducer can comprise putting in the mouthpiece and pressing a testsignal button on the communication device which then sends a test signalto the acoustical transducer, which converts the electrical signal to anaudio signal conducted through his teeth and skull, and which the diverthen listens for. For either test, the diver can move the mouthpiecearound in his or her mouth to find a position of the mouthpiece in theirmouth which yields the best audio input and/or electrical output signalfrom the microphone. The diver may perform a similar procedure forembodiments of the mouthpiece used in a snorkel. Having found thatposition, the diver may select a particular acoustic frequency or rangeof frequencies (e.g., akin to a channel) to use for input (hearing) andoutput (verbal speech). The diver may choose to use the systemunderwater for voice communication with other divers as well as surfaceship. Depending upon the frequencies available, the diver may thenselect/assign a distinct acoustic frequency or frequency range for aparticular diver as well as for a surface craft. In many embodiments,the system will allow for separate frequency and/or frequency range tominimize cross talk from diver to diver as well as diver to surface shipcommunication. These and other aspects, embodiments and features aredescribed in detail in the body of specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an embodiment of an underwater voicecommunication system for a diver.

FIG. 1 a shows an embodiment of a voice communication mouthpieceapparatus worn in the mouth and its use in the conduction of sound tothe inner ear through the skull.

FIG. 2 is a lateral view illustrating embodiments of the mouthpiececoupled to an underwater breathing apparatus such as a SCUBA.

FIG. 3 is a perspective view showing various features of an embodimentof the mouthpiece.

FIG. 4 is a lateral view showing an embodiment of the mouthpiece havingan electrical connection means such as a wire for coupling to portablewatertight electronic (PWE) devices such as a dive computer.

FIG. 5 a is a side cut-away view showing an embodiment of the mouthpiecehaving a cavity and a microphone positioned in the cavity.

FIG. 5 b is a block diagram illustrating the configuration and operationof an embodiment of the microphone.

FIG. 6 a is a side cut-away view showing an embodiment of the acoustictransducer comprising an electromagnetic driver, acoustical plate and aconnecting lever.

FIG. 6 b is a top down view showing an embodiment of the acoustictransducer positioned in/on the mouthpiece.

FIG. 6 c is a block diagram showing the configuration and operation ofan embodiment of the acoustical transducer.

FIG. 6 d is a block diagram showing the configuration and operation ofan embodiment of a communication system for generating voice prompts andother messages that are delivered to the diver by embodiments of theacoustical transducer.

FIG. 7 a is a top down view illustrating an embodiment of the acousticplate having a curved shape corresponding to curvature of the diver'sdental arches.

FIG. 7 b is a side view illustrating an embodiment of the acousticalplate having conducting ridges.

FIG. 8 illustrates an embodiment of the mouthpiece having a wirelesscommunication device such an RF communication chip for communicatingwith a diver computer or other PWE device.

FIG. 9 a is a cut away perspective view illustrating an embodiment of amultilayer mouthpiece having a rigid core and softer outer layer.

FIG. 9 b is a cut away top down view illustrating an embodiment of amultilayer mouthpiece having a rigid core and softer outer layer.

FIG. 10 is a schematic view illustrating the configuration and operationof an embodiment of the communication device for use with embodiments ofthe voice communication mouthpiece apparatus.

FIG. 11 is a schematic view illustrating the configuration and operationof an embodiment of a PWE device including a communication device foruse with embodiments of the voice communication mouthpiece apparatus.

FIG. 12 is a simplified block diagram illustrating an embodiment of thesystem including speech enhancement hardware in an underwater breathingapparatus to receive and recognize voice input and to produce a voiceoutput.

FIG. 13 is a simplified block diagram illustrating an embodimentincluding exemplary modules for recognizing voice input speech andproducing voice output.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-11, an embodiment of a communication system 5for voice communication from a first diver 200 to one or more otherdivers 210 or surface ships 220 comprises a voice communicationmouthpiece apparatus 10 (herein mouthpiece 10) and an underwatercommunication device 100. In various embodiments, communication systemalso provides for communication of computer generated voice messages tothe diver from a portable underwater device. Mouthpiece 10 is worn inthe diver's mouth and is configured to attach to a regulator 82 or otherfitting 83 of a self-contained underwater breathing apparatus (SCUBA) 80or other underwater diving apparatus. System 5, including mouthpiece 10,is configured to allow voice or other communication between a firstunderwater communication device 100 carried by diver 200 and a secondunderwater communication device 110 carried by other diver(s) 210 aswell as between communication device 100 and a communication device 130used by a ship 220. In one embodiment, communication device 130 can beincorporated into a buoy or array towed by ship 220. With regard tocommunication device 100 (and 110), it can be positioned on a variety oflocations on the diver and/or on SCUBA 80. In one embodiment, it may bepositioned on the diver's head and can be attached using a band or strapor it may be coupled to the hood of the diver's wetsuit. In manyembodiments, communication device 100 may be incorporated into aportable watertight electronic (PWE) device 160 carried or worn by thediver as is described herein.

In addition to communication with another diver 210 having a separateSCUBA 80, in various embodiments, system 5 and mouthpiece 10 can also beadapted for communication with another mouthpiece 10′ connected to abuddy breathing line 16 connected to same SCUBA 80 as used by diver 200as is shown in the embodiment of FIG. 1. In such embodiments,mouthpieces 10 and 10′ can be configured to both be operativelyconnected to the same communication device 100 or they may be configuredto be directly connected to each other without the use of communicationdevice 100. In use, such embodiments allow quick and ready communicationbetween the diver 200 and a buddy breather without the need for anycommunication device or any set up procedure.

The mouthpiece 10 includes a coupling element 11, an interior portion 20coupled to the coupling element 11, a microphone 40 and an acoustictransducer 50. Coupling element 11, couples the mouthpiece 10 to SCUBA80. In various embodiments, coupling element 11 may be configured tocouple directly to an air hose 81 of SCUBA 80 or a regulator 82 or otherfitting 83 of SCUBA 80. The coupling element 11 and the interior portion20 include a lumen 13 for the passage of respired air by the diver.

One or both of the microphone 40 and the acoustic transducer 50 may bepowered by a battery 90 which is incorporated into the mouthpiece 10 orcoupled to the mouthpiece 10, for example, by an electrical wire 17 orother electrical connection means. Battery 90 may comprise variouslithium buttons or other suitable batteries such as miniature batteriesknown in the art. Battery 90 may also be shaped to have a form factorwhich readily fits into mouthpiece 10. For example, in one embodiment,battery 90 may have curved shape which corresponds to the curvature ofthe diver's dental arches DA. Battery 90 may also be used to power aprocessor 70 that may also be contained in the mouthpiece 10.

Wire(s) 17 may also be configured to couple both the microphone 40 andthe transducer 50 (as well as other suitable electrical components ofmouthpiece 10) to various electrical devices that are part of SCUBA 80or are otherwise worn or carried by the diver, such as communicationdevice 100 and/or a dive computer 160. Wire(s) 17 may be insulatedsufficiently to withstand depths of several hundred feet or more. Aportion of the wires 17 may be embedded in the mouthpiece 10 and/orconnected to the mouthpiece 10 by an electrical connector configured forunderwater conditions. Wire 17 can include at least a first and secondwire for connection to the microphone 40 and the acoustic transducer 50.In some embodiments, a section of wire 17 may pass through lumen 13 ofcoupling element 11 so as to connect to one or more electrical devicesthat are part of SCUBA 80 or are otherwise worn or carried by the diver.In such embodiments, wire 17 is sufficiently thin or otherwiseconfigured so as to not interfere or impede the passage of respired airthrough lumen 13.

In alternative or additional embodiments, one or both of the microphone40 and the transducer 50 may be operatively coupled to communicationdevice 100 and/or dive computer 160 via use of a wireless communicationdevice, such as a radio frequency (RF) communication chip 95. RFcommunication chip 95 may correspond to an active or passive RFtransceiver and may be embedded in the mouthpiece 10. The frequency andpower levels for use with such an RF communication chip 95 can beadapted for underwater use to allow communication of signals 97 betweenthe RF communication chip 95 in the mouthpiece 10 and a correspondingchip 96 in communication device 100 and/or dive computer 160 carried bythe diver. In use, such embodiments, allow the diver to couple themouthpiece 10 to communication device 100 and/or computer 160 withouthaving to make any physical connections. They also allow the diver toverify that the mouthpiece 10 is operating properly before getting intothe water through the use of one or more diagnostic software modules 190resident within dive computer 160. The software modules 190 can beconfigured to interrogate mouthpiece 10 for proper operations. In oneembodiment, this may consist of the diver being prompted to speakseveral test phrases with the mouthpiece in place. Further, in variousembodiments, communication chip 95 may include memory resources 75coupled to chip 95 and may contain various diver specific information(e.g., name, weight, health data, dive history etc.), which can besignaled to dive computer 160 allowing the dive computer to uniquelyidentify the mouthpiece 10 as belonging to a particular diver and thenupload that data into the dive computer 160. The process may also befacilitated by use of a processor 70, such as microprocessor 70, whichcontrols the handshake and other communication between communicationchip 95 and chip 96. Processor 70 may also be coupled to memoryresources 75. In particular embodiments, such a configuration can beimplemented through use of an ASIC (application specific integratedcircuit) containing processor 70, and memory resources 75

The interior portion 20 of the mouthpiece 10 has a curved shape 21corresponding to a shape of the diver's dental arches DA and hasattached a right bite portion 31 and a left bite portion 32. Together,the right bite portion 31 and the left bite portion 32 form bitestructures 30. The curved shape 21 may be fabricated by taking a dentalimpression or image of the diver's mouth and then using that impressionor image to construct a mold for making the mouthpiece and/or usingstereolithography techniques known in the art. The bite structures 30include an upper surface 33 and a lower surface 34, which together formbite surfaces 35. The bite surfaces 35 are for engaging a bite surfaceBS of the diver's teeth T, including the diver's upper teeth UT (alsocalled maxillary) and lower teeth LT. Bite structures 30 may bepositioned and arranged to contact at least the back teeth of the diver,but may contact the front teeth or other teeth as well. The bitestructures 30 may also be acoustically isolated from each other byfabricating all or a portion of the bite structures from variousacoustically insulating materials known in the art.

In various embodiments, one or both of the bite structures 30 mayinclude a retaining flange 36 for retaining the mouthpiece in thediver's mouth M by contacting an inside surface of the diver's teeth.Typically, flange 36 will be oriented perpendicular to bite surfaces 35,but other orientations are also contemplated (e.g., an acute angle).Also, flange 36 may have a curved shape or profile 37 which correspondsto the curvature of the diver's dental arches DA.

In various embodiments, mouthpiece 10 may be fabricated from elastomericpolymers such as silicone, polyurethane, copolymers thereof and otherelastomers known in the art. The mouthpiece 10 may have a unitaryconstruction and or may be fabricated from separate components which arejoined. It may be fabricated using various methods known in the polymerprocessing arts, including molding and stereolithography methods. Also,molding may be done with the microphone 40 and/or acoustical transducer50 in place, or they may be added to cavities created in the mouthpiece10 for their positioning. The polymeric materials for the mouthpiece 10may be selected for several different mechanical and acousticalproperties. For example the material can be selected to achieve adesired durometer for the mouthpiece 10. The durometer of the materialmay be selected to maintain the shape of the mouthpiece 10, but at thesame time, reduce the bite force required for the diver to hold themouthpiece 10 in place. Suitable lower durometer embodiments, includethe range of 20 to 50, more preferably, 30 to 40. In use, such lowerdurometer embodiments allow the diver to keep the mouthpiece 10 in theirmouth for extended periods (e.g., hours) without excessive discomfort orfatigue of their jaw muscles, particularly while speaking. Theproperties of the polymers used for the mouthpiece 10 can also beselected to obtain a desired amount of acoustical insulation so as tominimize the transmission of sound from transducer 50 to microphone 40so as to reduce or prevent feedback between the two.

In some embodiments, the mouthpiece 10 having a lower durometer can beachieved by two ply and/or other multilayer configurations of themouthpiece 10 where at least a portion of the mouthpiece 10 comprises alower durometer tooth contacting surface layer 18 (also referred to as aliner) which fits over a higher durometer (e.g., more rigid), underlyingcore structure 19. The latter provides sufficient rigidity for holdingthe shape of the mouthpiece 10 in the diver's mouth, while the formerprovides a soft comfortable tooth contacting surface. Liner 18 may alsobe configured to provide acoustical insulation/dampening properties soas to reduce feedback between microphone 40 and transducer 50 byreducing the transmission of sound from transducer 50 and microphone 40.In use, such two ply or other multilayer embodiments of the mouthpiece10 provide a more comfortable mouthpiece and one that minimizes orreduces feedback from the transducer 50 and microphone 40, whilemaintaining the shape of the mouthpiece. In related embodiments,mouthpiece 10 can have a three or even a four ply construction toprovide additional amounts of acoustic insulation.

Microphone 40 is positioned in or on mouthpiece 10 and is configured todetect the sound 41 (herein voice sounds 41) from the diver's voice withthe mouthpiece 10 in place and generate an electrical output 42.Microphone 40 may comprise various miniature microphones known in theart and may comprise various electric microphones known in the art. Themicrophone 40 may include or be coupled to a preamplifier 47 as well asa filter device 43 for filtering out the diver's breath sounds or othernon-speech related sounds (e.g., bubble and cavitation sounds). Invarious embodiments, filter 43 may correspond to one or more of a highpass, low pass or band pass filter. Filter 43 may also be programmableto allow the user to select various acoustic criteria for filtering outbreathing sounds. Such criteria may include a particular frequencyrange, duration of sound and/or amplitude of sound that is filtered.Filter 43 may also be configured to filter out acoustic signals 52(discussed below) generated by acoustical transducer 50 so as tominimize feedback from transducer 50 and microphone 40. In analternative or additional embodiment, filter 43 may also be configuredas or include a switching device 43 s that shuts off the generation ofsignals 42 by microphone 40 when the diver is receiving signal acousticsignals 52 from transducer 50. In use, such embodiments provide anotherapproach and means for minimizing or eliminating feedback betweenmicrophone 40 and acoustic transducer 50.

Microphone 40 may be placed in any number of locations in or on themouthpiece 10. According to the present embodiments, microphone 40 isplaced on an opposite side 22 of the mouthpiece to the side thatcontains acoustic transducer 50 so as to minimize feedback between themicrophone and acoustic transducer 50 (side 22 being defined by thediver's left and right). In particular embodiments, the microphone isplaced on the opposite bite structure 30 from that of acoustictransducer 50. In such embodiments, bite structure 30 is configured todampen or attenuate any vibrations coming from acoustical transducer 50.Also, microphone 40 may also be placed on the surface 12 of mouthpiece10, but is more preferably recessed within the mouthpiece so as toattenuate breath sounds as well as reduce the likelihood of exposure toliquids in the diver's mouth.

In the embodiments of the mouthpiece 10 having a recessed microphone 40,the mouthpiece 10 can include a cavity 44 in which the microphone 40 isplaced. The cavity 44 may include a small aperture 45 or opening to themouthpiece surface 12 to allow for acoustical conduction to themouthpiece 10. The diameter of aperture 45 can be selected to minimizethe entry of fluids into the cavity, and in various embodiments, can bein the range of 0.001 to 0.00001 inches (0.00254 to 2.54e-005centimeter), and more preferably, 0.0005 to 0.0008 inches (0.00127 to0.002032 centimeter). In a specific embodiment, the diameter of aperture45 is 0.0007 inches (0.001778 centimeter). One or both of aperture 45and microphone 40 may include a waterproof layer 46, which maycorrespond to a porous material such as an expandedpolytetrafluoroethylene (PTFE) material. Also, in the embodiments of themouthpiece 10 having the cavity 44, the microphone 40 may also be pottedin cavity 44 with a sound insulating material, such as one or morecurable polymers having sound insulating properties (e.g., silicone). Inuse, such embodiments having the potted microphone 40 provide a meansfor reducing feedback between microphone 40 and acoustic transducer 50as well as for dampening of other unwanted sounds (e.g., from the diverclenching his jaw on the mouthpiece), which may be conducted throughmouthpiece 10.

Acoustic transducer 50 is positioned on the upper surface 33 of at leastone of the left and/or right bite structures 30. The acoustic transducer50 is configured to transduce an electrical signal input 51 (encoded orcorresponding to an acoustic signal) received by the diver'scommunication device 100 into an acoustic output signal 52. Input signal51 can be from one or more of another communication device 100 (e.g.,carried on either another diver or a surface ship), a dive computer, amusic player (e.g., an MP3 player) or other related devices. Inparticular embodiments, input signal 51 can be generated and/orconditioned by a processor 170 (described herein below) or other signalconditioning device or circuitry of communication device 100 or aprocessor 70 resident within mouthpiece 10. Processor 70 or 170 maycorrespond to a microprocessor and can be configured to generate, and/orcondition signal 51, as well as condition signal 42 from microphone 40.Such signal conditioning in either case can include one or more ofamplification, filtering, conversion, matching and isolation.

Transducer 50 is also configured to acoustically couple to the diver'supper teeth UT to conduct the acoustic output 52 from the diver's upperteeth through the diver's skull S to the diver's cochlea in order togenerate audible sound in at least one of the diver's ears E when thediver is wearing mouthpiece 10. In many embodiments, the transducer 50comprises an acoustical plate 53 (or a vibrating plate) coupled to adriver 54. The plate 53 is configured to engage with and is acousticallycoupled to the surface of the diver's teeth. The plate 53 is to bevibrated by the driver 54 responsive to electrical signal 51. Vibrationof the plate 53 produces acoustical signal output 52 which isacoustically conducted to the diver's teeth and then through the bonesin his or her skull S to the inner ear IE including cochlea C where theyare perceived as sound. Plate 53 can be fabricated from ceramic, metal,polymeric material such as a resilient polymer, and can have a size andshape to acoustically couple to one or more of the diver's teeth. Inparticular embodiments, plate 53 may have a curved horizontal shape 53 ccorresponding at least in part to the curvature of the diver's dentalarches DA to facilitate the plate contacting multiple teeth. Plate 53may also have one or more ridges or other raised feature 53 r configuredto enhance acoustical coupling and conduction to the diver's teeth. Inparticular embodiments, ridges 53 r can be positioned to contact thecenter depressions in the diver's teeth.

In particular embodiments, plate 53 can be configured to have anacoustical impedance approximating or otherwise matched in a certainfashion (e.g., proportional, inversely proportional, etc.) to that ofthe diver's teeth (e.g., one or more of the upper teeth). Suchembodiments can be achieved by fabricating plate 53 from one or moredental ceramics or other material having similar mechanical propertiesas the diver's teeth. Other acoustic properties can also be so matchedsuch as the resonant frequency of the plate and the teeth. Such matchingof acoustic properties can be configured to minimize acoustic lossesfrom plate 53 to the teeth or otherwise enhance conduction of acousticsignal 52 through the diver's skull S to the inner ear IE including thecochlea C.

In various embodiments, driver 54 comprises an electromagnetic driver55, which can be directly or indirectly coupled to plate 53. In theembodiments that driver 55 is indirectly coupled to plate 53, driver 54comprises the electromagnetic driver 55, a movable diaphragm 56 sittingatop or otherwise coupled to the driver 55, and a lever 57 or otherconnecting means coupling diaphragm 56 to plate 53. Electromagneticdriver 55 can comprise various electromagnetic drivers known in thespeaker or earphone arts and can comprise a miniature magnet 58 whichmay correspond to a core or coil. One or more of driver 55, movablediaphragm 56, lever 57 and magnet 58 can be fabricated frommicroelectromechanical-systems-based (MEMS-based) components eitherseparately or as a single structure. In alternative embodiments, driver55 may be configured to be directly coupled to plate 53 withoutdiaphragm 56 and/or lever 57.

Typically, acoustic transducer 50, including plate 53, is positioned toengage the upper (e.g., maxillary) back teeth of the diver's mouth M,but may be positioned to engage any suitable tooth or group of teeth inthe diver's mouth such as the front either upper or lower teeth. As anaddition or alternative embodiment, transducer 50 including plate 53 mayalso be configured to engage with and be acoustically coupled to thediver's upper palate (the hard palate). In such embodiments, the plate53 can have a curved shape matched to at least a portion shape of theupper palate (also known as the roof of the mouth). Such embodimentsallow for larger surface area of acoustical conduction to the diver'sskull and do not require the diver to bite down on the mouthpiece whenspeaking.

In various embodiments, mouthpiece 10 can include a sensor 60 which isconfigured to detect the diver's breath and generate an output signal61, which is used to switch off microphone 40 and/or to attenuate orgate the output signal 42 coming from the microphone to communicationdevice 100 during a time period of the diver's respiration (e.g., like asquelch function). In the first configuration (where the microphone isswitched off), the output signal 61 can be fed into microphone switchingdevice 43 s, and in the second signal 61 can be sent to communicationdevice 100 including processor 170. In many embodiments, sensor 60 cancorrespond to a miniature flow/velocity sensor for detecting a flow rateand/or velocity of the diver's breath moving through the mouth. When thevelocity or flow rate exceeds a threshold value, corresponding to flowrate or velocity of the diver's breath, the microphone 40 can beconfigured to shut off, and/or output signal 42 can be attenuated orgated by processor 170. The threshold value for flow rate and/orvelocity can be selected so as to be able to distinguish between avelocity or flow rate when the diver is speaking or breathing, theformer being lower than the latter. In various embodiments, processor170 and/or microphone 40 may include logic for shutting off themicrophone 40 and/or attenuating or gating signal 42 or 51. In specificembodiments, such logic for attenuating or gating signal 42 or 51 can beincorporated into one or more modules 190

For embodiments where sensor 60 comprises a flow sensor, the sensor canbe positioned in a variety of locations on mouthpiece 10 for detectingthe divers' breath. In preferred embodiments, flow/velocity sensor 60 isplaced toward the front section 14 of the mouthpiece 10 (e.g., near thefront teeth), preferably in the center 15 of the front section 14, so asto be in a location in the diver's mouth having the greatestvelocity/flow rate (for example, at the peak of a velocity profile suchas a velocity profile for Poiseuille flow). Such profiles can bedetermined using standard measurement methods known in the art for astandard mouth shape, size and tidal volume (or other relatedrespiratory measurement), with adjustments made for a particularindividual.

Communication device 100 can employ a variety of communicationmodalities including, for example, electromagnetic, RF, magnetic,optical, acoustical and/or combinations thereof. Referring nowparticularly to FIG. 10, in the preferred embodiments, the communicationdevice 100 can correspond to an ultrasonic or other acousticaltransmission device 100 a which transduces the electrical output signal42 into an acoustic signal 101, which is transmitted by the acousticaltransmission device 100 a. In such embodiments, communication devices100 can comprise one or more acoustical transducers 105 which transmitand/or receive acoustical energy at a selected frequency or range offrequencies. Selected frequencies can be in the range of 10 to 40 kHz,30 to 40 kHz, 100 to 200 kHz and 150 to 200 kHz. This frequency can beadjusted for one or more of the depth, salinity and temperatureconditions of the water. Acoustical transducers 105 may correspond toone or more ultrasonic transducers 106, which can comprise variouspiezo-electric materials, such as piezo-electric ceramic materials. Theparticular acoustical transducer 105 and acoustical frequency can beselected based on the desired acoustical transmission range, acousticalsensitivity, bandwidth, maximum diving depth, temperature and salinityconditions and related parameters.

Also, acoustical transducers 105 may be configured as both acousticaltransmitters and receivers so as to send and receive acoustical signals.In many embodiments, transducers 105 can be arranged as an array 107 oftransducers which may include a phased array formation. Array 107 can beconfigured to optimize one or more of the transmission range,sensitivity and bandwidth of communication device 100. In variousembodiments, the frequency, power settings and sensitivities oftransducers 106 and/or array 107 can be selected to enable underwatertransmission ranges for communication device 100 up to 1500 feet (457.2meters) and more preferably, up to 2500 feet (762 meters) or even greattransmission ranges. Also, communication device 100 can include signalgeneration and selection circuitry to allow for communication overmultiple selectable acoustic frequency ranges, herein after channels.Communication device 100 may also include a multiplexing device (notshown for simplicity) coupled to at least one of the transceiver orsignal processing circuitry so as to allow for the transmission and/orreceiving of multiple signals. The multiplexing device may be configuredfor one or more of time division, frequency division or code divisionmultiplexing. In alternative embodiments communication device 100 cancomprise an RF based device and can even include RF communication chip95 described above. In these and related embodiments, RF communicationchip 95 is configured to have a selected power and frequency to enableunderwater communication with other divers 210 and ship 220.

Referring now to FIG. 11, in many embodiments, communication device 100can be incorporated into a portable watertight electronic (PWE) device160. PWE device 160 will typically comprise a PDA (Personal DigitalAssistant) device or other similar device that is worn or carried bydiver 200. PWE device 160 may also comprise or be integrated into a divewatch, dive computer or other device or equipment carried by the diver,e.g., a flash light, depth gauge, regulator etc. For ease of discussion,PWE device 160 will now be referred to as a dive computer 160; however,other embodiments are equally applicable. Dive computer 160 includes aprocessor 170, display 180, user input means 185 and an electrical powersource 165. Power source 165 may correspond to a portable battery suchas a lithium or lithium ion battery or other batteries known in the art.User input means 185 may correspond to a touch screen which may beseparate from or integral with display 180. Processor 170 includes oneor more modules 190 including software programs or other logics forcontrolling various operations of device 160 including those ofcommunication device 100. For example, in various embodiments, module190 can comprise a program for discriminating between when the diver isspeaking versus breathing using an output 61 from sensor 60 and thengate or attenuate microphone output 42 and/or transducer output 51accordingly.

In other embodiments, module 190 can comprise a program or other logicinstruction sets for generating and sending various voice commands andother voice messages 102 to the diver to alert them of variousconditions and/or assist them in the performance of one or more tasks.In one embodiment, module 190 can comprise a program for the diverperforming a controlled ascent whereby the program sends voice promptsto the diver telling them how long to remain at a particular depthbefore they can ascend to the next depth so as to avoid decompressionsickness (also known as “the bends” or “divers' disease”) or otherrelated conditions. The program can be configured to send the prompts inresponse to one or more inputs such as those from an electronic depthgauge, electronic timer, SCUBA tank pressure or related gauge or sensor.Other inputs can include various messages from other divers 210 as wellas the dive boat or other surface ships 220.

The processor 170 will typically correspond to one or moremicroprocessors known in the art and can be selected for increaseddurability, fault tolerance and pressure resistance for underwateroperation, using various military-specification (MIL-SPEC) criteriaknown in the military/naval equipment arts. Processor 170 will typicallyinclude one or more modules or algorithms 190 for generating,conditioning and controlling signals sent to and from the mouthpiece 10,including signals 102 corresponding to voice messages as well ascontrolling other operations to allow two way voice communication bydiver 200. Modules 190 may also be configured for computing, monitoringand communicating various physiological data of the diver, including forexample, heart rate, respiration rate, blood pressure, blood oxygensaturation and other blood gas measurements (e.g., blood nitrogen).Processor 170 may also include other modules 190 which use such data todetermine if the diver is in a state of physiologic stress (e.g., suchas stress caused by low blood oxygen levels, “hypoxia,” or out gassingof nitrogen, “decompression sickness”) or a precursor state whichprecedes or is otherwise predictive of a state of physiological stress.When such a stress state or precursor state of stress is detected, itmay be communicated by the first communication device 100 to a secondcommunicative device 110 to allow other individuals (such as those onthe dive boat 220 or even those onshore) to monitor the diver(s) andalert them when it is time to ascend and/or if diver requiresassistance.

In particular embodiments, PWE device 160 can comprise a dive computeror a related device that is carried or worn by the diver and isconfigured to provide the diver 200 various voice messages 102 (alsoreferred to as spoken messages 102) including alerts, prompts andcommands using mouthpiece 10 and acoustic transducer 50. This can beachieved through the use of processor 170, audio signal generator 176,and one or more modules 190 that are configured to generate and signalvoice messages to the diver in response to one or more conditions and/oras part of a voice instruction set to the diver.

Referring to FIGS. 6 d and 10, in various embodiments, modules 190 caninclude a speech synthesizer module 191 which generates audio signals 51corresponding to voices messages 102. In use, such embodiments allow thediver to perform a number of tasks and activities, including variousmission critical tasks without having the distraction of having to lookat an instrument.

Speech synthesis module 191 can comprise various speech synthesisalgorithms known in the art. Additionally in various embodiments, speechsynthesis module 191 can include the capability for generating audiosignals 52, which correspond to a selected spoken voice 103. Spokenvoice 103 can include for example, the diver's own voice, or anotherperson's voice similar that used in aircraft navigation and controlsystems. One or both of modules 190 and 191 can include the capabilityfor the diver 100 to record specific messages 102 in their own voice orthat of another individual to allow module 191 to output those messagesto the another diver 210. Further, modules 190 and 191 may also includethe capability for the diver 200 to record a sufficient number ofvocalizations (in their own voice or that of another individual) toallow module 191 to generate any spoken message 102 and not just thosespoken by the diver 200 or other individual (e.g., the another diver210). The techniques for generating voices 103 from such vocalizationscan include various algorithms known in the speech synthesis arts, forexample, various concatenation routines 192 using stored speech units193 derived from the speaker's (e.g., the diver's) vocalizations. Suchroutines can be embedded within the programming of module 191 or theymay be external.

In an additional or alternative embodiment, modules 190 and 191 can alsoinclude the ability for the diver 200 to fine tune the voice 103 to haveselected acoustic properties (e.g., pitch, volume, etc. to theirliking). Such voice selection capability can be achieved by the use ofone or more algorithms incorporated into module 191 such as a pitchvariation algorithm 194, rate variation algorithm 195 (and otheradjustment algorithms known in the speech synthesis arts), which adjustaudio signals 51 to produce the desired voice 103. In use, suchembodiments allow the diver 200 to select a voice that they are mostcomfortable with and can mostly easily hear, particularly underwater. Insome embodiments, device 160 and modules 190, and 191 can include thecapability to allow the diver 200 to fine tune voice 103 while they areunderwater with the mouthpiece 10 in place. Accordingly, in variousembodiments device 160 can include various user input devices or othermeans 185 (e.g., knobs, touch screens, etc.) for making suchadjustments.

In addition to manual adjustment of voice 103, in various embodimentsdevice 160 can also include means for varying the acousticalcharacteristics of voice 103 depending upon variations in one or moreconditions experienced by the divers so as to maintain the diversability to hear messages 102 spoken by voice 103. Such conditions caninclude ambient noise levels, depth, water pressure and other likeconditions. Accordingly modules 191 can include one or more controlalgorithms 196 (e.g., PI, PID, etc.) which operate using an input 197which may comprise depth, pressure, ambient noise, etc. For the case ofambient noise levels, the input 197 can comprise signals 42 frommicrophone 42 or microphones coupled to device 160. In use, suchembodiments allow the diver to continue to hear commands 102 from voice103 during changes in their depth and in ambient noises level (e.g.,from a passing boat) which may otherwise drown out or reduce theacoustic fidelity of the voice. Module 191 can also adjust voice 103 aswell depending on the particular type of SCUBA 80, mask and mouthpieceused by the diver to account for variations in acoustical conduction andother acoustical characteristics.

Modules 191 can also be configured to modulate or otherwise adjust voice103 to account for reduced levels of conduction by bone of higheracoustic frequencies. This can be accomplished for example through theuse of pitch variations routines 195 which shifts the pitch of all or aportion of the frequency components of voice 103 to lower frequencies(e.g., make voice 103 deeper). In an additional approach for improvingconduction through the bone of the higher frequency components of voicemessage 102 or other acoustic signals 52 various embodiments of theinvention may use high pass signal routines implemented in hardware(e.g., a high pass filter coupled to op amp device) or in software by amodule 198 running on one or both of processor 170 and 70. Such anapproach (either in hardware or software) amplifies the higher frequencycomponents of voice 103 or other acoustic signal 52 by a selected gainwhich can vary depending upon the frequency (e.g., more gain for higherfrequencies). In one approach, the amount of the gain can be determinedby doing sound conduction readings through the diver's skull and/ortaking bone density readings using one or more bone densitometerinstruments known in the art.

Device 160 can send signals 51 to mouthpiece 10 using a variety ofmodalities. For example, in various embodiments, device 160 can sendaudio signals 51 containing modulating or otherwise encoding a voicemessage 102 to mouthpiece 10 via wires 17, or alternatively may do sowireless using an RF other wireless communication device 96. In anotherembodiment, a second device 160′ not directly coupled to mouthpiece 10can be used to acoustically signal voice messages 102 to device 160which is operatively coupled to mouthpiece 10 either via wires 17 orthrough use of RF communication devices 95 and 96.

As described above, various embodiments of the invention which generatespoken messages 102, for example using device 160, allow the diver toperform a number of tasks and activities, including various missioncritical tasks without having the distraction of having to look at gaugeor other instrument. Further, messages 102 can include not just datasuch as depth, remaining air, etc., but can include prompts forperforming one or more operations or tasks. For example, in one or moreembodiments, messages 102 can include spoken directions for reaching adesired location, such as a dive site, or the location of a dive boat orthat of other divers. Specific commands in such embodiments can includewithout limitation, “swim up,” “swim down,” “bear to the right,” “bearto the left,”. This allows the diver to navigate to such locations whilelooking at their surrounding and/or when there is minimal lighting.

In one or more exemplary embodiments, dive computer 160 andcommunication system 5 can be configured to provide the diver 200 withvoice messages 102 in the form of prompts for making a controlled ascentto the surface as to avoid the bends. Specifically, the dive computercould provide voice prompts telling the diver one or more of how long toremain at a particular depth during the ascent, what depth he is at, howlong he has been at the depth and how soon before he can ascend to thenext depth. The computer could also provide the diver with voice updatesproviding information such as their ascent rate and whether they need tostay longer or shorter at a particular depth depending on conditions. Inaddition to prompts and updates, the dive computer may also providevoice instructions of the entire ascent plan in advance allowing thediver to get a sense of the entire plan.

While in many embodiments, mouthpiece 10 is configured for use with aSCUBA 80, in other embodiments, the mouthpiece can also be configuredfor used with a snorkel or like apparatus, allowing a snorkeler to havetwo way voice communication with another snorkeler, diver 210 or ship220. In such embodiments, the entire system 5, including communicationdevice 100 can be contained in the mouthpiece 10. Further, in suchembodiments, the connecting portion 11 can be sized and shaped todetachably connect to a standard sized snorkel, allowing the diver toattach the mouthpiece 10 to an off the shelf commercial snorkel and havea skin diving version of underwater communication system 5. In stillother embodiments, mouthpiece 10 and system 5 can be adapted for usewith virtually any breathing apparatus such as that used by fire andmine rescue personal, so as to allow two way voice communications withsuch apparatus.

Referring to the embodiment in FIG. 12, a speech enhancement system 1202may be provided with or as an integrated part of an underwater breathingapparatus 1200. Accordingly, a combined system of speech enhancement1202 and underwater breathing apparatus 1200 can be devised in form of ascuba mask, mouthpiece, and/or add-on accessory.

In one embodiment, the underwater breathing apparatus 1200 includes amouthpiece (for supplying oxygen) and mask (not shown). The apparatus1200 may be integrated or combined with the speech enhancement system1202. Speech enhancement system 1202 includes voice input mechanism1210, speech enhancement hardware 1220, and voice output mechanism 1230.The input mechanism 1210 may correspond to a microphone, that is carriedwith the mask, mouthpiece or tubing. The input mechanism 1210 carriesunprocessed voice input 1212 to the speech hardware 1220. The speechhardware 1220 can include programming and/or logic to process the voiceinput 1212.

In an underwater operational environment, voice input 1212 can beassumed to be hindered by factors such as the presence of the mouthpieceand/or other aspects of breathing using an underwater breathing devicesuch as a SCUBA. Additionally, the user may be under physical stress orout of breath. In at least one implementation, speech enhancementhardware 1220 includes a processor coupled to the input mechanism.Speech enhancement hardware 1220 is configured to process a hinderedvoice input from the user.

Still further, in some embodiments, the speech hardware 1220 includessoftware or programming (e.g. a module) to recognize speech in itshindered form, and further to generate output that corresponds to acorrected or clarified version of the speech input. More specifically,the processor determines (or makes a probabilistic determination, i.e.,a guess) at what the user is intending to say. The processor thensignals a voice output 1222 that corresponds to corrected or clarifiedvoice output (e.g. unhindered simulated or synthesized speech).

A voice output mechanism 1230 may receive the processed output 1222 ofthe speech hardware resources 1220. The output 1222 may be transmittedto the output mechanism 1230, which may reside outside of the diver'spresence. For example, the output mechanism 1230 may be positioned withone or more other divers, surface ships, or to an underwater electronicdevice which generates voice messages for the diver.

In some implementations, the speech enhancement hardware 1220 includesone or more software modules that execute on processing resources (e.g.,a microprocessor) of speech enhancement hardware 1220. The modules maybe configured to facilitate performance of the system, such asproduction of voice output. Specific embodiments of speech enhancementhardware 1220 may include routines for recognizing input sounds (e.g.,phonemes, consonants, etc.) or even whole words which may becomegarbled, slurred or otherwise incomprehensible, due e.g., the diverspeaking with the breathing apparatus in place; matching those inputsounds to voice output sounds; and then, generating a voice output basedon those voice output sounds.

Voice output 1222 is produced by speech enhancement hardware 1220 andmay constitute any appropriate form in context of speech enhancementsystem 1220. For example, in various embodiments the voice output 1222may include an underwater signal to a receiver, electrical output, or a“blended” output comprising at least some of the voice input 1212 andsynthesized or simulated portions. The voice output can be in thespeaker's own voice (simulated), a synthesized voice or a combinationthereof. The former can be implemented by having the speaker record alibrary of speech sounds (also known as phonemes) including consonants,vowels, diphthongs, prefixes (e.g., “pre”), and suffixes (e.g. “ing”).Furthermore, in various embodiments of methods for matching voice inputto voice output, the diver can record pronunciation of each sound withand without the mouthpiece in place.

FIG. 13 illustrates an embodiment of speech enhancement comprisingreceiving voice input 1310, recognizing voice input speech 1320 andproduction of voice output 1330. The voice input 1310 may includehindered speech. Hindered speech includes speech that is garbled,slurred, impeded or otherwise made incomprehensible by the presence ofan underwater breathing apparatus. Voice input recognition 1320 may beperformed in a variety of ways, including those recited in the shownsub-steps of FIG. 13. For example, in Step 1322 (Word/Phrase Matching),a limited vocabulary may be preloaded. Also, speech recognition in Step1322 may comprise recognizing speech based on context, partial sounds,or other corresponding features of the input speech which, in someembodiments, may be associated with the preloaded vocabulary. As analternative or addition, Step 1320 may further comprise additional steps1324 (e.g., use of a phoneme library) or waveform analysis 1326.Recognizing the voice input may further comprise assigning similarityfactors for each characteristic, e.g., cadence 95% similar, volume 98%similar so that appropriate adjustments can be made for matching eachcharacteristic. These characteristics can be weighted and combined intoa composite characteristic with a composite similarity factor assignedas well. Such adjustments are particularly applicable for embodiments ofthe module utilizing a buffer to store the diver's speech, detect andprocess voice input to voice output and then blend the voice output intothe voice input.

In an embodiment, for each recording of the input speech, the modulegenerates and stores an audio signal waveform. The module can then usewaveform/pattern recognition routines to identify that waveform andmatch it to a voice output. In such an embodiment, the diver may makeseveral pronunciations for each sound so that the module can take anaverage of the voice input waveforms. For embodiments where the moduleuses waveform analysis, various curve fitting algorithms can be used todetermine an overall fit between a sampled sound and a known input sound(e.g., a hindered input “th” sound corresponding to a known output “th”sound). Such an approach allows for improved accuracy in matching avoice input to a voice output. Further, the module may also includealgorithms which adjust or otherwise take into account for the pressureand gas mixture that the diver is breathing (or other dive or breathingcondition) together which may affect the waveform of the voice input.

Voice output step 1330 may include a variety of sub-steps, including theproduction of an underwater signal to a receiver as in Step 1332,electrical output as in Step 1334, or blended output as in Step 1336.Step 1336 may comprise the voice output including at least some of thevoice input speech (“blending”). For example, where System 1300 includesmemory caches or a buffer, Step 1336 may comprise storing the diver'svoice input, substituting in the voice output sounds where appropriateand playing back the blended speech as a whole so that the listener doesnot hear any breaks in the diver's spoken messages. For example, asoftware module could be included in order to remove or otherwiseminimize any pauses in the voice output so that the blended speechsounds continuous to the listener. In performing such an operation themodule can take a sampling of the diver's speech to determine theaverage interval between words and then use that to look for gaps whichare larger than the average interval. In an embodiment, system 1330further includes routines for matching one or more characteristics ofthe voice output e.g., 1230, to the voice input e.g., 1212 so that thedifferences between the two are not readily discernible to the listener.Such characteristics can include without limitation the cadence or speedof the speech, pitch of the speech, volume of the speech (amplitude) orother related property.

The foregoing description of various embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to limit the invention to the precise forms disclosed. Manymodifications, variations and refinements will be apparent topractitioners skilled in the art. For example, various embodiments ofthe communication system 5 including the mouthpiece 10 can be adaptedfor salt and fresh water environments, as well as deep dives (e.g., 60to 200 meters (196.9 to 656.2 feet)) and cold water environments. Theymay also be adapted for use in closed circuit re-breathers in additionto standard SCUBA equipment.

Elements, characteristics, or acts from one embodiment can be readilyrecombined or substituted with one or more elements, characteristics oracts from other embodiments to form numerous additional embodimentswithin the scope of the invention. Moreover, elements that are shown ordescribed as being combined with other elements, can, in variousembodiments, exist as standalone elements. Hence, the scope of thepresent invention is not limited to the specifics of the describedembodiments, but is instead limited solely by the appended claims.

What is claimed is:
 1. A system for enhancing speech, the systemcomprising: an input mechanism to receive a first voice input from afirst user; a communication device to transmit and receive acousticsignals across a liquid medium and to generate an electrical signalbased on received acoustic signals; a transducer to convert theelectrical signal into an acoustic output; wherein the transducer isconfigured to be coupled to the first user's upper teeth to generateaudible sound in at least one of user's ears; and a processor configuredto: receive the first voice input from the first user; recognize speechof the first user based on the first voice input; and output arespective acoustic vocal signal to the communication device based onthe speech.
 2. The system of claim 1, wherein the first voice input is ahindered voice from the first user wearing an underwater breathingapparatus.
 3. The system of claim 2, wherein the underwater breathingapparatus comprises the input mechanism.
 4. The system of claim 3,further comprising a self-contained underwater breathing apparatus(SCUBA), and wherein the underwater breathing apparatus is coupled tothe SCUBA.
 5. The system of claim 1, wherein the transducer isconfigured to conduct the acoustic output from the first user's upperteeth through the first user's skull to generate the audible sound, andwherein the communication device is further to process the electricalsignal to increase conduction of the acoustic output at higher frequencylevels.
 6. The system of claim 1, wherein the received acoustic signalscorrespond to a second voice input from a second user.
 7. The system ofclaim 1, wherein the processor is further configured to provide therespective acoustic vocal signal output in a synthesized voice.
 8. Thesystem of claim 7, wherein the processor is further configured tosupplement the first voice input with a synthesized input to generate acomposite audio output signal so as to provide the respective acousticvocal signal output in the synthesized voice.
 9. The system of claim 8,wherein the synthesized voice is selectable to vary in pitch or volumein response to an input.
 10. The system of claim 9, wherein the inputcomprises a diving depth, ambient noise level, air supply gas mixture,air supply amount, air supply pressure, air supply flow rate, or rate ofascent by a diver.